IntroductionAlthough some magnetic resonance imaging (MRI) studies have investigated the existence of a relationship between clinical severity and neuroanatomical alterations in patients with schizophrenia (SCZ), the biological signature associated with illness severity in schizophrenia is still uncertain.ObjectivesThis study aims to investigate structural brain abnormalities in SCZ with particular regards to the identification of potential deficits associated to the severity of illness.Methods1.5 T MRI data were acquired for 61 subjects with SCZ and 59 matched healthy controls (HC). The patient group was divided in two subgroups based on clinical severity, one composed by 34 mild-to-moderately ill patients and the other one by 27 severely ill patients, and compared with matched HC.ResultsThe whole group of patients with SCZ had significantly reduced gray matter (GM) volumes in left inferior and middle temporal gyrus compared to HC (P < 0.05, pFWE corrected). Furthermore, compared to HC, patients with mild-to-moderate illness showed decreased GM volumes in inferior temporal gyrus (P < 0.05, pFWE corrected) whereas those with severe illness had reduced right cerebellum (P < 0.05, cFWE corrected). No differences were observed between the two subgroups of patients.ConclusionsOur results showed significant GM volume reductions in left inferior and middle temporal gyrus in patients with SCZ compared to matched HC, confirming the role of this region in the pathophysiology of SCZ. Furthermore, we identified specific cerebellar gray matter volume reductions in patients with severe illness, which may contribute to stratify patients with SCZ according to their clinical phenotype expression, ultimately helping in guiding targeted therapeutic/rehabilitation interventions.Disclosure of interestThe authors have not supplied their declaration of competing interest.